中文摘要：

针对斜拉桥异形主塔钢混结合段的特殊构造特点和施工工艺要求，结合安徽涡河三桥工程，对C50高性能自密实微膨胀混凝土的配合比进行试验研究。在此基础上，考虑不同外加剂、掺合料掺量等因素对钢混结合段内混凝土性能的影响，进行配合比优化试验并得到钢混结合段混凝土配合比。结果表明：膨胀剂掺量对混凝土工作性能影响较大，掺量为10％时混凝土性能最佳。本试验结果有效解决了钢混结合段入模难、易收缩开裂等技术难题，为同类结构的自密实混凝土配合比试验提供了参考。

英文摘要：

In consideration of specific constructional characteristics and technology requirements of steel-concrete composite sections of cable-stayed bridge with special shaped tower, C50high performance of self-compacting micro expansion concrete mixture proportion were studied, based on practical project Anhui Guohe River Bridge.It also presents the reasonable mixture proportion for steel-concrete composite section via tests on specimens with different contents of additives.The results indicate that expanding agent has great impact on concrete performance, with best property when content is 10%.The results can effectively solve the technical problems of the steel concrete compos- ite, such as the difficulty of entering the mold, easy to shrink, and so on.It also provides a reference for mixture ratio test for the similar structure of self-compacting concrete.